Genome-wide evidence of host specialization in wild and farmland populations of the Cercospora leaf spot pathogen, Cercospora beticola

Domestication of plants has been a continuous human endeavor since the dawn of agriculture more than 10.000 years ago. One of the most recent crop species to be domesticated is sugar beet (Beta vulgaris L. ssp. vulgaris Doell.), which was bred for high sucrose content within the last few centuries in Europe for its high sucrose content. Crop domestication can also lead to the evolution of novel pathogen lineages, resulting in disease epidemics. In this study, we addressed the recent evolution of the Cercospora leaf spot agent, Cercospora beticola, a pathogen that is increasingly important in sugar beet and table beet production worldwide. To this end, we used genome sequences of 326 C. beticola isolates collected from four continents from four closely related Beta subspecies (three domesticated and one wild).